JP2007028760A - Manufacturing method for stator core of claw pole motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method with which the accuracy of bending a pole tooth relative to a flange can be enhanced with respect to a stator core piece of a claw pole motor and thus the motor characteristics of the claw pole motor can be improved. <P>SOLUTION: The method for manufacturing the stator core of a claw pole motor, having an annular flange and a pole tooth that is folded from the inner circumferential surface of the flange and is disposed along the central axis of the flange orthogonal to the flange face includes the steps of: forming multiple pole teeth protruded in the direction of the inside diameter of the flange; forming folding auxiliary machined portions at the base of the pole teeth; folding the pole teeth toward the central axis of the flange with the folding auxiliary machined portions as starting points; and punching the outline of the flange out of core piece material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stator core of a claw pole motor that manufactures a stator core piece having an annular flange and pole teeth that are bent from the inner periphery of the flange and are perpendicular to the flange center axis. More particularly, the present invention relates to a method for improving the bending accuracy of pole teeth.

  The stator core of the stepping motor includes, for example, a laminated stator core formed by laminating a plurality of core pieces punched from electromagnetic steel sheets, and a stator core of a claw pole type motor disclosed in Patent Document 1 below. This claw pole type motor is used in personal computers and printers.

As shown in FIGS. 7 and 8, the stator core piece 1 used in the claw pole type motor has a plurality of pole teeth 12 protruding in the inner diameter direction of an annular plate (flange) 11 with respect to the flange surface. The stator core piece 10 is formed by bending in the direction of the orthogonal flange center axis (rotor installation axis) C, and the pole teeth 12 of the two stator core pieces 10 are aligned with each other with the flange center axes of the two stator core pieces 10 aligned. It is formed by meshing and filling a gap between the pole teeth 12 with a resin (not shown). Furthermore, a stator is manufactured by winding a coil around the cylindrical part of the stator core 1 formed by the meshed pole teeth 12.
Japanese Patent Laid-Open No. 7-31123

  By the way, the claw pole type motor has the advantage of reducing the manufacturing cost, but also has the following problems.

  That is, in the formation of the stator core piece, the pole teeth are bent in the direction of the flange central axis in order to make the bending angle of the pole teeth a right angle. The bending angle of each pole tooth varies due to internal residual stress caused by bending or the like, and the position accuracy of the pole tooth is deteriorated (see pole tooth 12 'in FIG. 7B). As a result, the gap between the individual pole teeth of the stator core and the rotor core disposed inside the stator core does not become constant, resulting in inconvenience that the motor characteristics of the claw pole motor are deteriorated. .

  In order to reduce the step angle, it is necessary to increase the number of pole teeth. However, if the number of pole teeth is increased, the width of the pole teeth becomes narrower, and a displacement occurs in the inner circumferential direction of the flange during bending. It becomes easy. If a stator core is manufactured using a stator core piece having such pole teeth, the gap between adjacent pole teeth will not be constant, so the step angle of the claw pole motor equipped with this stator core will also be It will not be constant. In other words, in order to make the step angle constant, the pole teeth of the claw pole type motor need to have a width that does not shift in the inner circumferential direction of the flange. For this reason, the step angle of the claw pole type motor cannot be reduced, and the motor characteristics may be deteriorated.

  The present invention has been made in view of the above circumstances, and can improve the accuracy of bending the pole teeth with respect to the flange of the stator core piece of the claw pole type motor, thereby improving the motor characteristics of the claw pole type motor. It is an object to provide a method that makes it possible.

  In order to achieve the above object, a method of manufacturing a stator core of a claw pole motor according to the invention of claim 1 includes an annular flange, a flange center bent from an inner periphery of the flange, and perpendicular to the flange surface. In a method of manufacturing a stator core of a claw pole type motor for manufacturing a stator core piece having a pole tooth along an axis, a step of forming a plurality of pole teeth protruding in an inner diameter direction of the flange, and the pole tooth Forming a bending assisting portion at the base end of the sheet, a step of bending the pole teeth in the direction of the center axis of the flange starting from the bending assisting portion, and a step of extracting the flange from the core piece material. It is characterized by comprising.

  A method of manufacturing a stator core of a claw pole type motor according to the invention of claim 2 is the method of manufacturing a stator core of a claw pole type motor according to the invention of claim 1, wherein after the step of bending the pole teeth, The base end portion of the pole teeth is pressed so that the pole teeth are perpendicular to the flange surface.

  A method of manufacturing a stator core of a claw pole type motor related to the invention of claim 3 is the method of manufacturing a stator core of a claw pole type motor related to the invention of claim 1 or claim 2, wherein the bending auxiliary processing portion is , A groove extending over the entire width of the pole tooth on the back surface or the front and back surfaces of the pole tooth, or a notch positioned along the circumferential direction on both side edges of the pole tooth. .

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a stator core for a claw pole motor according to the first or second aspect of the present invention. The groove extends over the entire width of the pole teeth, and the depth of the end portion in the inner circumferential direction of the flange is deeper than the depth of the central portion.

  According to the first aspect of the present invention, when a bending auxiliary processing portion is formed at the base end portion of the pole tooth, and the pole tooth is bent starting from the bending auxiliary processing portion, the pole tooth is perpendicular to the flange surface and the flange tooth. It can be bent with high accuracy without being displaced in the inner circumferential direction. For this reason, the dispersion | variation in a pole tooth is suppressed and it becomes possible to make the gap of a stator iron core and a rotor iron core constant. Furthermore, since the combination accuracy of the stator core pieces is increased, when the stator core pieces are manufactured by combining the stator core pieces, the gap between adjacent pole teeth becomes constant. Therefore, since the number of pole teeth can be increased by narrowing the pole teeth of the stator core, the step angle can be reduced. That is, the characteristics of the claw pole type motor can be improved.

  Further, as in the invention of claim 2, when the base end portion of the pole tooth is pressed after the pole tooth is bent, the pole tooth is deformed due to an internal residual stress caused by springback, punching, bending, or the like. Even if it occurs, since the pole teeth can be corrected at right angles to the flange surface, the accuracy of the stator core piece is improved. That is, the characteristics of the claw pole type motor can be further improved.

  Further, as in the invention of claim 3, the bending auxiliary processing portion is a groove extending over the entire width of the pole tooth on the back surface or front and back surfaces of the pole tooth, or circumferentially on both side edges of the pole tooth. By forming the notch located along the stator core, the stator core piece can be easily formed, and the right-angle bending accuracy of the pole teeth can be improved. That is, the characteristics of the claw pole type motor can be further improved.

  Further, when both end portions of the groove are made deeper than the central portion as in the invention of claim 4, when the pole teeth are bent starting from the groove, the excess core piece material generated in the central portion escapes to both end portions. This further improves the right-angle bending accuracy of the pole teeth. That is, the characteristics of the claw pole type motor can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
Fig.1 (a) has shown the state which looked at the stator core piece 10 of the claw pole type motor before bending a pole tooth from the surface side. As shown in FIG. 1A, the stator core piece 10 includes an annular flange 11 and a plurality of pole teeth 12 protruding in the inner diameter direction of the flange 11. A groove 13 as a bending assisting processing portion is formed on the back surface side of the base end portion 12 a of each pole tooth 12, and this groove 13 extends over the entire width of the pole tooth 12 and along the inner circumferential direction of the flange 11. It extends and the cross-sectional shape of the groove 13 in the longitudinal direction of the pole teeth 12 has a rectangular shape.

  In addition, the stator core piece 10 is manufactured by forming the pole teeth 12 on the strip-shaped steel plate (iron core piece material) W and then removing the flange 11 from the outer shape in a progressive die apparatus having processing stations A to E. The

  Below, the manufacturing process of the stator core piece 10 is demonstrated later on using FIG.

  First, at the processing station A, after punching the central hole of the strip steel plate W, at the processing station B, a plurality of pole teeth 12 are punched and formed on the inner periphery of the flange 11. Incidentally, the central hole punching and the punching of the pole teeth 12 may be performed simultaneously.

  Next, after forming the groove 13 in the base end portion 12a of each pole tooth 12 by coining or the like at the processing station C, at the processing station D, each pole tooth 12 is bent and formed in the flange central axis direction as will be described later.

  In addition, coining etc. which form the groove | channel 13 may be performed after the center hole punching of the strip steel plate W and before the pole teeth 12 are formed.

  That is, when bending each pole tooth 12 in the processing station D, as shown in FIG. 3A, the groove 13 formed in the base end portion 12a of the pole tooth 12 is formed in the hole provided in the die 31. It is installed along the opening of 31 a, the surface side of the strip steel plate W (flange 11) is pressed by the stripper 32, the punch 33 is moved down, and each pole tooth 12 is pushed inside the hole 31 a provided in the die 31. Go.

  At this time, a groove 13 as a bending assisting portion is formed in the base end portion 12a of the pole tooth 12, and the pole tooth 12 is easily bent starting from the groove 13, so as shown in FIG. The pole teeth 12 can be accurately bent substantially perpendicular to the flange 11. Further, since the pole teeth 12 are bent while being guided by the grooves 13 when being pushed into the holes 31 a provided in the die 31, the pole teeth 12 can be bent accurately and easily without being displaced in the inner circumferential direction of the flange 11. It becomes.

  After bending the pole teeth 12 at the processing station D, the flange 11 is extracted from the strip steel plate W at the processing station E. The manufacturing of the stator core piece 10 is completed through the above steps.

  Incidentally, as described above, the stator cores are obtained by meshing the pole teeth 12 with each other in a state where the flange central axes of the two stator core pieces 10 are aligned with each other, and filling the gaps between the pole teeth 12 with resin. Is manufactured. Further, the stator is manufactured by winding a coil around a cylindrical portion of the stator core formed by the meshed pole teeth 12.

  As described above, when a bending assisting portion is formed at the base end portion of the pole tooth, and the pole tooth is bent starting from the bending assisting portion, the pole tooth is perpendicular to the flange surface and the inside of the flange. It can be bent with high accuracy without being displaced in the circumferential direction. For this reason, the dispersion | variation in a pole tooth is suppressed and it becomes possible to make the gap of a stator iron core and a rotor iron core constant. Furthermore, since the combination accuracy of the stator core pieces is increased, when the stator core pieces are manufactured by combining the stator core pieces, the gap between adjacent pole teeth becomes constant. Therefore, since the number of pole teeth can be increased by narrowing the pole teeth of the stator core, the step angle can be reduced. That is, the characteristics of the claw pole type motor can be improved.

  By the way, when the stator core piece is formed as described above, if the rigidity of the core piece material is strong, even if the pole teeth are bent, the stator core piece may be deformed by the spring back of the core piece material. In order to cope with such an inconvenience, it is effective to correct the deformation of the stator core piece by pressing the base end portion of the pole tooth after bending the pole tooth.

  That is, even if the pole teeth 12 are bent starting from the groove 13, the pole teeth 12 may be deformed as shown by the broken line shown in FIG. . In this state, the proximal end portion 12a of the polar tooth 12 is pressed in the bending direction of the polar tooth 12 as shown by an arrow A shown in FIGS. By deforming, the pole teeth 12 are corrected to a predetermined bending posture as shown by the solid line in FIG. The pressing of the base end portion 12a may be performed at any time after the pole teeth 12 are bent.

  Thus, after bending the pole teeth, pressing the base end of the pole teeth will cause the pole teeth to be deformed even if the pole teeth are deformed due to internal residual stress due to springback, punching, bending, etc. Since it can be corrected at right angles to the flange surface, the accuracy of the stator core piece is improved. That is, the characteristics of the claw pole type motor can be further improved.

  In the embodiment described with reference to FIGS. 1A and 1B, the groove 13 having a rectangular cross-sectional shape in the longitudinal direction of the pole teeth 12 is formed. However, the present invention is limited to the above-described embodiment. Is not to be done.

  That is, as shown in FIG. 5A, the cross-sectional shape of the groove 13 as the bending assisting processing portion may be V-shaped. In short, it is sufficient that a groove is formed in the base end portion 12a of the pole tooth 12, and there is no need to particularly limit the cross-sectional shape.

  Further, as shown in FIG. 5B, grooves 13 and 13 as bending assisting processing portions may be formed on both the front and back surfaces of the base end portion 12 a of the pole teeth 12. Further, although not shown, a groove as a bending assisting processing portion may be formed on the surface side at the base end portion of the pole tooth.

  Further, as shown in FIG. 5C, V-shaped notches 14 and 14 are formed on both side edges of the base end portion 12a of the pole teeth 12 as bending assisting processing portions positioned along the circumferential direction. May be.

  By making the bending auxiliary processing portion a groove extending over the entire width of the pole tooth on the back surface or the front and back surfaces of the pole tooth, or by making a notch positioned along the circumferential direction on both side edges of the pole tooth The stator core pieces can be easily formed, and the right-angle bending accuracy of the pole teeth can be improved. That is, the characteristics of the claw pole type motor can be further improved.

  Furthermore, as shown in FIG. 6, the depth of the groove 13 extending over the entire width of the pole tooth 12 and along the inner circumferential direction of the flange 11 may be partially changed. Both end portions 13a and 13a of the groove 13 are formed deeper than the central portion 13b.

  When both ends of the groove are deeper than the center, when the pole teeth are bent starting from the groove, the excess core piece material generated at the center escapes to both ends, so that the right-angle bending accuracy of the pole teeth is improved. Further improve. That is, the characteristics of the claw pole type motor can be improved.

(A) is a top view of the stator core piece of a claw pole type motor, (b) is a perspective view of a pole tooth. It is a top view of the strip | belt-shaped steel plate which showed the manufacturing process in each station in the apparatus which manufactures the stator core piece of a claw pole type motor. (A) is a figure which shows the bending process of the pole tooth in the station D of FIG. 2, (b) is a figure which shows the pole tooth after a bending process. It is a figure which shows the state which presses the base end part of a pole tooth after a bending process. (A), (b), (c) is a figure which shows another form of a bending auxiliary process part. It is a figure which shows another form of the bending auxiliary process part different from FIG. (A) is a top view of the stator core piece of the conventional claw pole type motor, (b) is a side view of the stator core piece with pole teeth bent. It is a side view of a stator core.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Stator core piece, 11 ... Flange, 12 ... Polar tooth, 13 ... Groove, 14 ... Notch.

Claims (4)

A method for manufacturing a stator core of a claw pole type motor that manufactures a stator core piece having an annular flange and pole teeth that are bent from the inner periphery of the flange and are perpendicular to the flange center axis. In
Forming a plurality of pole teeth protruding in the inner diameter direction of the flange;
Forming a bending assisting portion at the base end of the pole tooth;
A step of bending the pole teeth in the direction of the center axis of the flange starting from the bending assisting portion;
Removing the flange from the core piece material;
A method for manufacturing a stator core of a claw pole type motor, comprising:   2. The fixing of the claw pole type motor according to claim 1, wherein after the step of bending the pole teeth, the base end portion of the pole teeth is pressed so that the pole teeth form a right angle with the flange surface. A manufacturing method of a child iron core.   The bending auxiliary processing portion is a groove extending over the entire width of the pole tooth on the back surface or the front and back surfaces of the pole tooth, or a notch positioned along the circumferential direction on both side edges of the pole tooth. 3. A method of manufacturing a stator core of a claw pole type motor according to claim 1, wherein the stator core is provided.   The bending auxiliary processing portion is a groove extending over the entire width of the pole tooth, and the depth of the end portion in the inner peripheral direction of the flange is formed deeper than the depth of the central portion. A method for manufacturing a stator core of a claw pole type motor according to claim 1 or 2.

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